1. Field of the Invention
The invention relates to coffee brewing devices; and, more particularly, to a foldable single cup disposable coffee brewing device adapted to be placed on top of a coffee cup or mug.
2. Description of the Prior Art
Various types of coffee brewing devices are well known in the art. Various types of coffee filters are known in the art. In U.S. Pat. No. 4,863,601, to Wittekind, et al., one such exemplary filter is disclosed for use with a single cup. In this patent, a rather expensive filter is used to filter the brewed coffee. In U.S. Pat. No. 5,095,185 to Fuchs, a single cup coffee brewing device is disclosed having a valve on the filter body to control the flow of brewed coffee. This valve is temperature controlled but is a bimetallic strip that might give a metallic taste to the brewed coffee and is expensive to manufacture and install. Other suitable device are disclosed in U.S. Pat. Nos. 4,948,601; 5,132,124; 5,055,311; 4,981,588; 5,168,140; 5,059,325; 5,064,980; 4,908,222; 4,697,503; 4,867,880; 4,986,172; 4,996,066; 5,082,676; and 5,010,221. Except for the last two prior art patents, none of these remaining patents shows an element associated with the filter that dissolves when the water in the reservoir reaches a desirable brewing temperature and/or has been retained therein for a desirable brewing time. The 5,010,221 patent to Grossman, et al. does have a non-toxic heat responsive sealing substance adapted to releasably seal a partition in a closed position. However, the filter body is not foldable and the partition must be made to specific dimensions, then sealed in position by beeswax or the like. In U.S. Pat. No. 5,064,980 to Grossman, et al., a similar sealed partition is disclosed in a non-foldable filter container. Further, the beeswax melts almost immediately and thus does not retain the hot water in contact with the coffee grounds for a sufficient period of time. Applicant's device obtains a richer cup of coffee with less coffee grounds than Grossman, et al. might require.
There thus exists a need for a single cup disposable and foldable coffee brewing device which can hold heated water in contact with coffee grounds in the filter, then brew the same into a cup or mug.